Summary

A vulnerability in the Border Gateway Protocol (BGP) functionality of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause all BGP sessions on the device to reset.

The vulnerability is due to the improper processing of specifically crafted BGP update messages. An attacker could exploit this vulnerability by crafting a specific BGP-labeled update message. An exploit could allow the attacker to cause all the BGP peers on a Cisco NX-OS device that are configured with either a VPNv4, VPNv6, or IPv6 labeled unicast address family to reset.

Cisco has confirmed the vulnerability in a security notice and released software updates.

To exploit this vulnerability, it is likely that an attacker would need access to trusted, internal networks in order to send crafted BGP update messages to be processed by the targeted device. This access requirement may reduce the likelihood of a successful exploit.

Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.

Affected Products

Customers are advised to consult Cisco bug ID CSCuj03174 for the most complete list of affected product versions.

Vulnerable Products

At the time this alert was first published, Cisco NX-OS Software versions 6.2(2a) and prior were vulnerable. Later releases of Cisco NX-OS Software may also be vulnerable.

Products Confirmed Not Vulnerable

No other Cisco products are currently known to be affected by these vulnerabilities.

Workarounds

Administrators are advised to apply the appropriate updates

Administrators are advised to allow only trusted users to have network access.

Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.

Administrators are advised to monitor affected systems.

Fixed Software

Cisco customers with active contracts should contact their Cisco support team for assistance in upgrading to a software version that includes fixes for this vulnerability. Cisco customers without contracts may contact the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at tac@cisco.com for assistance.

Exploitation and Public Announcements

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Cisco Security Vulnerability Policy

To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

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Revision History

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Cisco Security Vulnerability Policy

To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.